Prostaglandins have a diverse range of activities and have a well recognized role in inflammation. Prostaglandin D2 (PGD2) is produced by mast cells, macrophages and Th2 lymphocytes in response to local tissue damage and/or inflammation and/or infection related to ocular diseases or conditions. PGD2 binds to a number of receptors, which include the thromboxane-type prostanoid (TP) receptor, PGD2 receptor (DP, also known as DP1) and chemoattractant receptor-homologous molecule expressed on Th2 cells (CRTH2; also known as DP2). In Th2 lymphocytes, IL-4, IL-5 and IL-13 cytokine production is stimulated. These cytokines have been implicated in numerous biological actions including, by way of example only, mucous secretion, inflammation and/or eosinophil recruitment. Ophthalmic pharmaceutical compositions comprising DP2 receptor antagonists, administered to any ocular tissue of a mammal, are used to treat or prevent DP2-dependent or DP2-mediated diseases or conditions.